SST and Heparin tubes are no longer suitable tube types for this assay.
Units: nmol/L
Reference intervals:
17-OH-progesterone, nmol/L
(MS)
females: less than 9.0
males: less than 6.0
age
0 to 3 months
less than 9.0
3 months to 10 years (pre-pubertal)
less than 3.5
10 years and older
Uncertainty of Measurement: < 5nmol/L 26%
>= 5 nmol/L 22%
Performed Weekly.
If an urgent test is required for CAH in babies, National Testing Centre can test a dried blood spot. Analysed daily, or urgently if required. Contact laboratory.
Principle: Tandem Mass Spectrometry
Assay: In-house
Analyser: Shimadzu LC-MS/MS
17-OH-progesterone concentrations are highest at birth, decrease rapidly in the first week of life, and remains low from 3 months until puberty. Levels may be raised for long periods in premature infants and are frequently elevated in sick neonates.
Patients with congenital adrenal hyperplasia (CAH) have a deficiency in one of the enzymes in the biosynthetic pathway for the production of cortisol. The most common defect is 21-hydroxylase deficiency. The high concentrations of 17-hydroxyprogesterone in CAH result in an increased production of androstenedione and testosterone . These androgens can cause ambiguous genitalia in newborn females, virilisation in older females and precocious puberty in males. Severe enzyme blocks can cause insufficient mineralocorticoid synthesis and salt-wasting which can be fatal if not treated promptly.
Late onset (non-classical) 21-hydroxylase deficiency is a milder enzyme defect which can cause hirsuitism in adolescent or adult females. The diagnosis can be confirmed with an ACTH (synacthen) stimulation test.
Carriers of 21-hydroxylase deficiency (heterozygotes) have a smaller response in 17-hydroxyprogesterone following ACTH stimulation which may overlap those with normal genotype.
|
SYNACTHEN (ACTH) STMULATION TEST 17-OH-progesterone (nmol/L) |
basal | post-ACTH |
|
Normal genotype |
see above |
less than 9 (MS) |
|
non-classic (late onset) enzyme deficiency |
3-400 (MS) |
90-400 (MS) |
| Carriers (heterozygotes) of CYP21A2 | ---------------- |
2-50 (MS) |
References :
1. Pang S. Congenital adrenal hyperplasia. Endocrinol & Metabolism Clinics of N America 26 (1997) 853-891.
2. Soldin, O. P., H. Sharma, et al. (2009). "Pediatric reference intervals for aldosterone, 17alpha-hydroxyprogesterone, dehydroepiandrosterone, testosterone and 25-hydroxy vitamin D3 using tandem mass spectrometry." Clin Biochem 42 (9): 823-827.
3. Fanelli, F., A. Gambineri, et al. (2013). "Androgen profiling by liquid chromatography-tandem mass spectrometry (LC-MS/MS) in healthy normal-weight ovulatory and anovulatory late adolescent and young women." J Clin Endocrinol Metab 98 (7): 3058-3067.
4. Rauh, M., M. Groschl, et al. (2006). "Automated, fast and sensitive quantification of 17 alpha-hydroxy-progesterone, androstenedione and testosterone by tandem mass spectrometry with on-line extraction." Steroids 71 (6): 450-458.
5. Kulle, A. E., M. Welzel, et al. (2013). "Implementation of a liquid chromatography tandem mass spectrometry assay for eight adrenal C-21 steroids and pediatric reference data." Horm Res Paediatr 79 (1): 22-31.
6. Kyriakopoulou, L., M. Yazdanpanah, et al. (2013). "A sensitive and rapid mass spectrometric method for the simultaneous measurement of eight steroid hormones and CALIPER pediatric reference intervals." Clin Biochem 46 (7-8): 642-651.
7. Costa-Barbosa, F. A., V. F. Tonetto-Fernandes, et al. (2010). "Superior discriminating value of ACTH-stimulated serum 21-deoxycortisol in identifying heterozygote carriers for 21-hydroxylase deficiency." Clin Endocrinol (Oxf) 73 (6): 700-706.
Emails to chemicalpathologist@adhb.govt.nz will receive priority attention from the on-call chemical pathologist.
If the query concerns a specific patient please include the NHI number in your email.
If email is not a suitable option, please contact the on-call chemical pathologist via Lablink (Auckland City Hospital ext. 22000 or 09-3078995).
Individual chemical pathologists may be contacted but will not be available at all times.
After-hours : contact Lablink (Auckland City Hospital ext. 22000 or 09-3078995) or hospital operator for on duty staff after hours.
Dr Samarina Musaad (Clinical Lead) : SamarinaM@adhb.govt.nz ext. 22402
Dr Cam Kyle: CampbellK@adhb.govt.nz ext 22052
Dr Weldon Chiu: WeldonC@adhb.govt.nz ext. 23427
Dr Campbell Heron: CHeron@adhb.govt.nz ext. 23427
Dr Sakunthala Jayasinghe: Sakunthala@adhb.govt.nz ext. 23427
| Sample |
Serum - Plain EDTA plasma (SST and Heparin tubes are NOT suitable) |
| Sample Preparation |
Centrifuge and aliquot - 500uL Freeze |
| Sample Stability |
Room temperature up to 24 hours Refrigerated up to 4 days Freeze if more than 4 days |
| Transport to LabPlus |
Send refrigerated up to 4 days Send frozen if more than 4 days |
Reference:
1. Griffith C, Owen L, Keevil B. (2008). Stability of testosterone and androstenedione in refrigerated serum samples. Annals Clin Biochem 45 (Suppl 1): 107